Apparatus for trimming a specimen which is to be cut in a microtome

ABSTRACT

There is provided an apparatus in which a specimen containing an object embedded therein can be trimmed to a shape and size suitable for cutting in a microtome. The apparatus includes a specimen holder, a cutting means and means for causing relative movement between the cutter and the specimen. Means are found which enable the specimen holder to be turned so that any side of the specimen can be presented at will to the cutter, and means by which adjustment can be made to the relative position of cutter and specimen thereby to enable the specimen to be cut to a predetermined cross-sectional shape.

United States Patent [72] Inventors Karl-Erik Wistedt Jakobsberg; Bo Giista, Forsstriim, Skalby, Sweden, and Karl Goran Algy, Persson, Stockholm,

Sweden [21] Appl. No. 847,543 [22] Filed Aug. 5, 1969 [45] Patented Oct. 12, 1971 [73] Assignee IKB-Producter AB Bromma, Sweden [54] APPARATUS FOR TRIMMING A SPECIMEN WHICH IS TO BE CUT IN A MICROTOME 4 Claims, 9 Drawing Figs.

[52] US. Cl 90/24 R, 8 3/9 15.5 [51] Int. Cl 823d 3/04 [50] Field of Search 90/34-37,

[56] References Cited UNITED STATES PATENTS 805,700 1 1/ 1905 Avril 90/245 1,355,780 12/1920 Richards 90/32 2,600,591 6/1952 Wang 90/32 Primary ExaminerJames M. Meister Attorney-McGlew and Toren ABSTRACT: There is provided an apparatus in which a specimen containing an object embedded therein can be trimmed to a shape and size suitable for cutting in a L microtome. The apparatus includes a specimen holder, a

cutting means and means for causing relative movement between the cutter and the specimen. Means are found which enable the specimen holder to be turned so that any side of the specimen can be presented at will to the cutter, and means by which adjustment can be made to the relative position of cutter and specimen thereby to enable the specimen to be cut to a predetermined cross-sectional shape.

PATENTEU BBHZISYI 361L875 SHEET 1 [1F 2 QTT RNE Y5 APPARATUS FOR TRIMMING A SPECIMEN WHICH IS TO BE CUT IN A MICROTOME The present invention is concerned with an apparatus for trimming a specimen which is to be cut in a microtome. The specimen comprises a cylindrical body for example, made of plastic or some other material which can be readily cut, having the specimen which it is desired to examine under a microscope embedded therein. The specimen is trimmed partly inorder to remove superfluous portions of plastic material therefrom and partly to impart to the specimen a shape which permits the cuts made in the microtome to obtain the desired configuration. The specimen is normally trimmed to the shape of a pyramid, e.g. having square cross section,

whereby the sliced sections obtain the same shape as the mentioned cross section.

The specimen has previously been trimmed by hand; and the object of the invention is to provide an apparatus which facilitates this process and which enables sections to be cut in the microtome exactly to a predetermined shape and size.

The apparatus of the invention includes a specimen holder means, in which the specimen is mounted, a knife or blade for cutting the specimen means for providing relative movement of the specimen and the knife, and is characterized in that the specimen holding means is arranged for rotation on a support, to enable the desired side of the specimen to be presented to the knife. Preferably there is also provided an index, adapted to indicate the position of the specimen holder means on the support. The index is suitably provided with markings which represent the cross-sectional shape of the trimmed specimen.

When reference is made in the following description and claims to relative movement of the specimen and the knife by the drive means it is implied that the knife may be stationary and the specimen movable or vice versa.

The invention will now be described with reference to the accompanying drawing, in which FIGS. l-3 show three cuts of different configuration,

FIG. 4 shows how a specimen is trimmed if it is desired to obtain the square cut illustrated in FIG. 1,

FIG. 5 shows the apparatus of FIG. 4 seen in the directions of the arrows V-V,

FIG. 6 is a view corresponding to that of FIG. 5, the cuts obtained being given the trapezoid shape illustrated in FIG. 2,

FIG. 7 shows an embodiment of the apparatus of the invention,

FIG. 8 shows on enlarged scale the specimen holder and the knife in the apparatus of FIG. 7, and

FIG. 9 shows a section through the line IXIX in FIG. 7.

FIG. I shows a square-shaped section, FIG. 2 a trapezoid section and FIG. 3 a section in the shape of a regular pentagon. FIG. 4 shows how a specimen 1 is trimmed so as to obtain the square shape illustrated in FIG. I. The specimen is cylindrical, and is mounted in a holder 2. An object 4 is embedded in the specimen. The holder 2 can be turned about an axis 9, can be caused to move in the direction of arrows I and be caused to effect a reciprocatory movement normal to the plane of the paper. A knife 3 is placed with the edge 3a thereof positioned at the desired angle to the axis of rotation 9. The specimen holder 2 is moved up and down and at the same time to the left, i.e. towards the knife which cuts the specimen 1 into relatively thin slices. This operation is continued until the final, desired surface is obtained. The specimen holder 2 is then moved to the right, turned through 90", and the described trimming process is repeated until the surface 6 is obtained. Surfaces 7 and 8 are obtained in a corresponding manner. The specimen 1 thus obtains the shape of a regular pyramid having four sides, so that when the specimen is cut in a microtome by causing relative movement of the knife and specimen at right angles to the axis of the pyramid, a square-shaped section is obtained.

FIG. 6 illustrates in a view corresponding to that of FIG. 5 the manner in which the specimen is trimmed to obtain a section in the shape of a trapezoid. The dotted lines are perpendiculars to the sides of the trapezoid. The desired pyramidal surfaces are obtained by turning the holder 2 in sequence through the angles V,, V V and V,

In the apparatus shown in FIG. 7 the specimen holder 2 is mounted on one end of an arm 11. The other end of the arm is attached by means of a leaf spring 12 to an arm 13 whose upper end is fastened by means of a leaf spring 14 to a bracket 15 affixed to the frame 16 of the apparatus. The lower end of the arm 13 bears against a stud 18 positioned at the lower portion of an arm 17, the lower end of which is connected to the frame-l6 by means of a leaf spring 19. The upper end of the arm 17 is in contact with one end of a longitudinally movable but nonrotatable rod or bar 20. The other end of the rod 20 is provided with a thread which coacts with an internal thread in a sleeve 50. The sleeve 50 is supported by a spindle 21 which is capable of being driven, via a bevel gear 51, by a spindle 22 extending perpendicular to the spindle 21 and rotated by a crank. Rotation of the spindle 2] causes the rod 20 to move longitudinally, thereby causing the arms I3 and 17 to be moved via the arm 11. The spindle 22 is provided with an cecentric 23, around which is joumaled a ring 24 by means of a ball bearing. Extending around the ring 24 is a wire 25 whose ends are attached to the arm 11. Consequently, as the spindle 22 rotates, the arm 11 will move up and down, and will also move in its longitudinal direction.

The manner in which the specimen holder is attached to the specimen arm 11 is best seen in FIG. 8. The specimen holder 2 is secured in a member 26, which has the shape of a segment of a circle and the center of which is located in the apex of the specimen 1, and can be locked at'any desired position relative to the member 26 by means of a screw 27. The segmental member 26 is attached to an arm 28, which is rotatably mounted in the arm II. The arm 28 is provided with shallow recesses 29 with which engages a ball 30 biassed by means of a spring 31, whereby the arm can be readily adjusted to predetermined positions.

The end surface of the arm II is provided with an annular indicating means or index 32 cooperating with a mark 33 on the arm 28, thereby enabling the position of the specimen holder to be read off. The index 32 includes two series of markings, namely one series of four markings 340-344! in the form of squares, and one series of four markings 350-3511 in the form of trapezoids. The number of markings in each series is equal to the number of sides in the pyramid to which the specimen is to be shaped. When preparing a pyramid having a square cross section, as shown in FIG. I, the specimen holder is rotated each time through and the markings 34 are accordingly placed 90 apart, on the annular indicator 32. When preparing a pyramid having a trapezoid cross section, as shown in FIG. 2, the specimen holder is rotated through angles of size V and V the markings 35 being interspaced accordingly at distances of V, and V;,, as shown in FIG. 9.

The knife 3, which shapes the specimen to pyramid form, is mounted in a knife holder 36 which contains three knives. The knives comprise known glass knives, consisting of a plate having the shape of a triangle. The upwardly turned edge 3a is the cutting edge of the knife. The knives are held in position by being pressed against an intermediate wall 39 in the knife holder, by a screw 40. The knife holder 36 is mounted for rotation on a plate 41, to enable the knife of choice to be turned to working position. The plate 41 is arranged for movement in the direction of arrow 45 on a plate 43 and can be locked in any desired position by means of a screw 42. The plate 43 is capable of moving on the frame of the apparatus in the direction of arrow 46, and can be locked in position by a screw 44. The knives can be set in this way to any desired position.

The knife holder 36 is able to accommodate three similar knives, or knives presenting different cutting edge angles, or knives which are mounted so as to present different clearance angles.

The apparatus of FIG. 7 also includes a lamp 47 mounted in a holder 48 capable of being turned about an axis 49 which extends through the apex of the specimen 1. The lamp thus constantly illuminates the specimen irrespective of the position of the lamp holder.

When trimming a specimen, the knife is adjusted so that its edge 3a forms the desired angle to the axis of rotation 9 of the specimen holder. This angle determines the angle of the vertex of the pyramid to which the specimen is to be shaped. The specimen holder is then set to the desired position on the segmental member 26, depending for example on the location of the object 4 in the specimen l. Trimming is now effected in the manner described with reference to FIG. 4, by rotating the spindle 22. Subsequent to shaping the specimen into the form of a pyramid, the knife can be adjusted so that its edge 3a is normal to the axis of the pyramid, and the trimming process can be continued until the object 4 lies at the surface of the specimen. The specimen can now be transferred to a microtome or can be sliced in the trimming apparatus itself, which can thus be used as a microtome.

We claim:

1. An apparatus for trimming a specimen to be cut in a microtome, comprising a base, a knife holder mounted on said base, means for fastening at least one knife in said knife holder, a specimen arm having one end pivotally fastened to said base, means for imparting a reciprocating motion to the other end of said specimen arm, a circle segment holder rotatably mounted on said other end of the specimen arm, means for turning the circle segment holder around its axis of rotation and to fix it in predetermined positions, and a specimen holder mounted in said circle segment holder, means for fixing the specimen holder in any desired position in said circle segment holder, the specimen being situated in the center of said circle segment holder and on said axis of rotation of the circle segment holder.

2. An apparatus as claimed in claim 1, comprising means for moving the specimen arm in its longitudinal direction.

3. An apparatus as claimed in claim 2, in which the first end of the specimen arm is fastened to the means for moving the specimen arm in its longitudinal direction by means of a leaf spring.

4. An apparatus for trimming a specimen to be cut in a microtome, comprising a base, a knife holder mounted on said base, means for fastening at least one knife in said knife holder, a specimen arm, means for causing relative movements between the specimen arm and the knife, a circle segment holder mounted on one end of the specimen arm, a specimen holder mounted in said circle segment holder, means for turning one of the circle segment holder and the specimen holder and to fix it in a predetermined position, means for fixing the specimen holder in any desired position in said circle segment holder, the specimen being situated in the center of said circle segment holder and on the axis of rotation of one of the circle segment holder and the specimen holder. 

1. An apparatus for trimming a specimen to be cut in a microtome, comprising a base, a knife holder mounted on said base, means for fastening at least one knife in said knife holder, a specimen arm having one end pivotally fastened to said base, means for imparting a reciprocating motion to the other end of said specimen arm, a circle segment holder rotatably mounted on said other end of the specimen arm, means for turning the circle segment holder around its axis of rotation and to fix it in predetermined positions, and a specimen holder mounted in said circle segment holder, means for fixing the specimen holder in any desired position in said circle segment holder, the specimen being situated in the center of said circle segment holder and on said axis of rotation of the circle segment holder.
 2. An apparatus as claimed in claim 1, comprising means for moving the specimen arm in its longitudinal direction.
 3. An apparatus as claimed in claim 2, in which the first end of the specimen arm is fastened to the means for moving the specimen arm in its longitudinal direction by means of a leaf spring.
 4. An apparatus for trimming a specimen to be cut in a microtome, comprising a base, a knife holder mounted on said base, means for fastening at least one knife in said knife holder, a specimen arM, means for causing relative movements between the specimen arm and the knife, a circle segment holder mounted on one end of the specimen arm, a specimen holder mounted in said circle segment holder, means for turning one of the circle segment holder and the specimen holder and to fix it in a predetermined position, means for fixing the specimen holder in any desired position in said circle segment holder, the specimen being situated in the center of said circle segment holder and on the axis of rotation of one of the circle segment holder and the specimen holder. 